Researchers at the Gwangju Institute of Science and Technology, South Korea, have claimed that they have developed a new method to increase perovskite solar cells’ efficiency by utilizing ions.

The researchers said perovskite solar cells are thin, light, and have a high conversion efficiency of over 25%. However, the efficiency decreases because of the defects in the organic-inorganic complex perovskite materials.

In its report, they explained that defects inside perovskite material have a charge that could be divided into positive electric and negative electric charges. Researchers used a passivation method to control this charge using a material with one charge or unshared electron pair. But only one type of charge can be passivated through this method.

The researchers used L-alanine as an additive to perovskite materials to passivate defects and increase grains in perovskite solar cells to overcome the problem. They confirmed that solar cell efficiency increased to 20.3% from 18.3%.

The report confirmed that the improvement in device efficiency was due to inhibition of nonradiative recombination of perovskite materials through photoluminescence spectroscopy – a contactless and non-destructive method of probing the electronic structure of materials – and time-related single-photon calculation techniques.

Kwanghee Lee, the lead researcher, said that the research suggested a new principle that can resolve defects inside materials with a zwitterion molecule. “This is expected to be applicable not only to the solar cell field but also to various semiconductor devices like light-emitting diodes, transistors, optical sensors using mixed organic and inorganic perovskites.”

In October 2020, a research team from the Australian Research Council Center of Excellence in Exciton Science claimed that they had developed a process that can help enhance perovskite cells’ commercial use.

Mercom had earlier reported that a research team from the Iowa State University came up with a technique that made perovskite solar cell material more stable at higher temperatures.